Fail safe snap acting disconnect switch



y 1965 l. EPSTEIN. I 3,194,909

FAIL SAFE SNAP ACTING DISCONNECT SWITCH Filed March 28, 1962 3Sheets-Sheet 1 INVENTOR.

ISRAEL EPSTEIN ATTORNEY y 13, 1965 l. EPSTEIN 3,194,909

FAIL SAFE SNAP ACTING DISCONNECT SWITCH Filed March 28, 1962 3Sheets-Sheet 2 INVENTOR.

ISRAEL EPSTEIN ATTORNEYS F /'g. 5 B

July 13, 1965 l. EPSTEIN 3,194,909

FAIL SAFE SNAP ACTING DISCONNECT SWITCH Filed March 28, 1962 5Sheets-Sheet 5 INVENTOR.

ISRAEL EPSTEIN ATTORNEY United States Patent 3 194 909 nan. SAFE SNAPAca nsc nrscoNNnc'r swrrcn Israel Epstein, Cleveland, (lhio, assignor toThe Clark Controller Company, Cleveland, Ohio, a corporation of OhioFiled Mar. 28, 1962, Ser. No. 133,128 6 Claims. (Cl. 2ll067) Myinvention relates to electric switches and more specifically to adisconnect switch of the fusible and nonfusible type.

It is an object of my invention to provide a disconnect switch havingcontacts that are positioned in an arc chamber and yet wherein theposition of said contacts is visible to the operator.

It is another object of my invention to provide a disconnect switchcapable of readily and easily accommodating fuses of various ratings.

It is a further object of my invention to provide a disconnect switchwherein the contacts are opened or closed with a snap action.

it is still another object of my invention to provide a disconnectswitch that is capable of being operated by means located at its frontor means located at its side.

Still another object of my invention is to provide a disconnect switchhaving a minimum number of co1nponent parts and which may be easilyassembled.

Still another object of my invention is to provide a switch that can beoperated to the olf position should the spring break when the switch isin the on position.

It is still a further object of my invention to provide a switch whereinthe operating means cannot be moved to the off position should thecontacts of the switch become welded closed.

Still other objects of my invention will become apparent to thoseskilled in the art when the following specification is viewed in lightof the accompanying drawings in which:

FIGURE 1 is a front View of the disconnect switch;

FIGURE 2 is a view taken on line 22 of FIGURE 1;

FlGURE 3 is a side view of the switch when viewed in the direction ofarrows 3-3 in FIGURE 1 and with the fuse block removed and a portion ofthe contact housing removed to show the operating arm;

FIGURE 4 is a View of the contact arm and the associated stationary andmovable contacts;

FIGURE 5 is a rear view or" the switch showing the operating mechanismin the off position;

FIGURE 6 is a rear view of the switch showing the operating mechanism inthe on position; and

FIGURE 7 is a rear view of the switch with the operating mechanism inthe oil position and the additional mechanism required to make saiddisconnect switch side operated.

As shown in FIGURE 1, the disconnect switch consists of a base it?having downward turned edges with a contact housing 11 mounted on oneend thereof and a fuse block 12 mounted on the other end thereof.Contact housing 11 is formed of insulating material and has three arechambers l3, l4 and 15 formed therein spaced apart rela ion and openingoutwardly thereof.

Arc chamber 13 has a stationary contact 16 therein which is formed onone end of bus member 17. Bus member 17 extends out of arc chamber 13and upwardly from contact housing if. and has a terminal 13 secured onits external end. A second stationary contact 19 is positioned in spacedapart relationship with stationary contact 16 and is formed. on one endof a bus member 20. Bus member 20 extends out of arc chamber 13 anddownwardly to be positioned on a portion of contact housing 11 forinsulated support thereof.

ice

Are chamber 1d has a stationary contact 21 therein which is formed onone end of a bus member 22. Bus member 22 extends upwardly out of arcchamber 14 from contact housing 11 and has a terminal 23 secured on itsexternal end. A second stationary contact 24 is positioned in spacedapart relationship with contact 21 and is formed on one end of a busmember 25. Bus member 25 extends downwardly out of arc chamber 14 to bepositioned on a portion of contact housing 11 for insulated supportthereof.

Arc chamber 15 has a stationary contact 26 therein which is formed onone end of a bus member 27. Bus member 2'7 extends upwardly out of arcchamber 15 from contact housing 11 and has a terminal 28 secured on itsexternal end. A second stationary contact 29 is positioned in spacedapart relationship with stationary contact 26 and is formed on one endof a bus member 3%. Bus member 3% extends downwardly out of arc chamber15 to be positioned on a portion of contact housing 11 for insulatedsupport thereof.

A movable contact 31 is positioned for reciprocal movement between twopositions in are chamber 13 by means to be described. in one positionmovable contact 31 bridges stationary contacts 16 and 19 and in thesecond position, it opens the circuit between said stationary contacts16 and 19.

A movable contact 32 is positioned for reciprocal movement between twopositions in arc chamber 14 by means to be described. Inone position,movable contact 32 bridges stationary contacts 21 and 24 and in thesecend position, it opens the circuit between said stationary contacts21 and 2 3.

A movable contact 33 is positioned for reciprocal movement between twopositions in arc chamber 15 by means to be described. In one position,movable contact 33 bridges stationary contacts 26 and 29 and in thesecond position, it opens the circuit between said stationary contacts26 and 29.

Terminals 18, 23 and 28 are of the type having a screw 34 for retainin awire or wires thereby to provide an electrical connection.

Bus members 28, 25 and have a plurality of holes 35 therein for thepurpose of securing a plurality of different fuse clips thereon.

Contact housing 11 is secured to base 10 by means of screws 36 extendingthrough base in and screwing into the bottom of contact housin iii (seeFIGURE 5).

Fuse block 12 is positioned on the other end of base it and is made ofinsulating material and is secured thereto by means of screws 37extending through base in and screwing into the bottom of fuse block 12(see FEGURE 5). Fuse block 12 has bus members 38, 39 and 49 positionedthereon in spaced apart relationship. Said bus members 38, 3? and 49each have a plurality of holes 41 therein for securing a plurality ofdifferent fuse clips thereon. Each bus member has a terminal 42positioned thereon for securing wires thereto to provide an electricalconnection therewith.

The pairs of bus members, 2% and 38, 25 and 39, and 3d and ill, one ofwhich is on the contact housing 11 and the other on fuse block 12, arealigned with each other to permit a fuse to be connected thereacrosswhen appropriate fuse clips are individually mounted on said pairs ofbus members. Also, fuse block 12 may be moved on base l9 so the switchmay accommodate different size fuses. V

The disconnect switch has a toggle lever arm 43 of eneral L-shapedrotatably secured to the front of base it) by means of a pin 44 (seeFIGURE 5) at the point of connection of its two legs. A portion oftoggle lever arm 43 is positioned under contact housing 11. The

short leg 45 of L-shaped toggle lever arm 43 is formed in the shape of aU-bracket. Said U-bracket 45 has aligned holes in both legs thereof forreceiving and securing thereto operating arm 46. A portion 47 ofoperating arm 46 extends through said U-bracket 45 and through anarcuate slot 48 in base 19. Operating arm 46 extends outwardperpendicular to said base 16 and through a recess formed in contacthousing 11 and is provided with suitable means for operating said switchfrom the front thereof. The purpose of U-bracket 45 is to provide twopoints of connection with operating arm 46 and thereby increase thestrength thereof.

The end 49 of the other leg of toggle lever arm 43 is S-shaped in adirection to extend through an arcuate slot 50 in base 10. Thus, end 49of toggle arm 43 is positioned below base 16. A slot 51 is punched inthe middle bend of end 49 and a hole 52 is punched in the last bend forpurposes to be described.

Thus, it is seen that when operating arm 46 is rotated, it moves in apath about pin 44 and causes toggle lever arm 43 to rotate about pin 44through arcuate slot 50. The ends of slot 50 serve as a means forstopping the rotative movement of toggle lever arm 43 and operating arm46.

As shown in FIGURE 5, a crank actuator 53 is rotatably attached by meansof a pin 54 to the bottom of base 10. Crank actuator has twoears 55 and56 formed on one side thereof and a downwardly and outwardly turned car57 (S-shaped) on the other side thereof. Bar '57 has a slot 58 (showndotted) formed therein. A mechanical stop 59 is secu'red to the bottomof base 16 by welding or other suitable means and positioned betweenears 55 and 56 to prescribe the limits for the rotative movement ofcrank actuator 53.

Crank actuator 53 has a slot 60 formed in the main body thereof andspaced at a distance from pin 54. The purpose of slot 60 will bedescribed hereinafter.

Connected between end 49 of toggle lever arm 43 and crank actuator 53 isa lever arm 61. Lever arm 61 has a fork end 61A at one end thereof whichstraddles ear 57 of crank actuator 53. Lever arm 61 is rotatably securedto crank actuator 53 by means of a pin 63 which is inserted through slot58. The other end of lever arm 61 is inserted through slot 51 in thedownward turned end 49 of toggle lever arm 43. A spring 62 circumscribesa portion of lever arm 61 and reacts between said fork end 61A and thedownward turned end 43 of toggle lever arm 43 to apply a rotative forceon crank actuator 53 by means of pin 63. As shown in FIGURE 5, the forceof spring 62 is in a direction to rotate crank actuator 53 about pin 54in a counterclockwise direction, however, such movement is prevented byear 55 engaging stop 59.

With reference to FIGURE 3, there is shown a support member 64 securedby suitable means on base 16 and projecting therefrom to be positionedin a recess 64A formed in the bottom of contact housing 11. Supportingmember 64 has a pin 65 secured thereto and said pin 65 rotatablysupports a crank 66. Crank 66 has one end 67 thereof which extendsdownward through an opening 68 in base and into the slot 66 located incrank eases actuator 53. The other end 69 of crank 66 is fork-shaped andcapable of receiving'a pin 70 between the prongs of said fork. Legs 67and 69 of crank 66 are at a suitable angle with each other for thepurpose of transform- 'ing the rotative movement of crank actuator 53into a vertical movement for pin 7 6.

Pin 70 is molded in contact carrier arm '71. Contact carrier arm 71 islocated in an aperture in said contact housing 11 beneath theaforementioned arc chambers as shown in FIGURES 2 and 3. Contact carrierarm 71 itself -is better shown in FIGURE 4.

Contact carrier arm 71 has three upwardly extending fingers formed onits top, 72, 73 and 74. Contact carriers 75, 76 and 77 are inserted infingers 72, '73 and 74,

respectively. Movable contacts 31, 32 and 33 are placed over contactguides 75, 76 and 77, respectively, and are resiliently held against thetop side of said fingers by means of springs 78 which circumscribe saidfingers. A spring retaining washer 79 is positioned over said fingersand retained thereto by well known means.

With the switch in the condition shown in FIGURE 1, that is, the contactopen position, the mechanism at the rear of base 16 is in the positionillustrated in FIGURE 5. To move the switch to its on condition, it isonly necessary that operating arm 46 be rotated clockwise as viewed inFIGURE 1. The rotation of operating arm 46 causes toggle lever arm 43 tomove clockwise rotatably about its point of pivotal connection, pin 44.Toggle lever arm 43 rotates about pin 44 until its end 49 strikes theother end of arcuate slot 50, stopping any further movement of it oroperating arm 46.

This operation as viewed in FIGURE 5 causes end 49 of toggle lever arm43 to rotate in the counterclockwise direction through arcuate slot 50.Rotative force must be continually applied to rotating arm 46 until thecenter line axis of lever arm 61, pin 63 and pin 54 are all aligned witheach other. Up until this time the force of spring 62 is in an upwarddirection to maintain crank actuator 53 in its original position withear 55 against stop 59. Immediately upon passing the aforedescribedcenter line aligned position, pin 63 immediately moves to the other endof slot 58 causing the force of spring 62 to react on crank actuator 53on its other side of its point of pivot, pin 54. This change indirection of the force of spring 62 causes crank actuator 53 to rotateclockwise about pin 54 until car 56 engages stop 59 as is shown by FIG-URE 6. It is to be noted that slot 66 in crank actuator 53 has beenmoved down due to the aforedescribed rotative movement.

The downward movement of slot causes end 67 of crank 66 to move downwardand rotating crank 66 about pin 65, thereby moving fork end 69 and 79towards base 10. Contact operating arm 71 is thereby moved downward,causing movable contacts 31, 32 and 34 to engage with their respectivestationary contacts. Additional downward movement of contact arm 71 isprovided so springs 78 are compressed and thereby applying pressurebetween said movable and stationary contacts.

When the mechanism has passed over center, the resulting movement of theparts occur with a snap, causing the contacts to close with a snapaction.

Conversely, to move the switch from the on position to its off position,operating arm 46 as viewed in FIG- URE 1 is rotated in thecounterclockwise direction. Again, this causes toggle lever arm 43 torotate about pin 44 in the counterclockwise direction. This movementcontinues until end 49 of toggle lever arm 43 engages the other end ofarcuate slot 50.

\Vhen viewed from the rear of base 10, the mechanism moves from theposition indicated in FIGURE 6 to that indicated in FIGURE 5.

It is to be noted as viewed in FIGURE 6 the force of spring 62 reacts ina somewhat horizontal direction beloW the point of pivot for crankactuator 53.

As operating arm 46 is rotated counterclockwise, end 49 of toggle leverarm 43 as viewed in FIGURE 6 is rotated clockwise. Rotative force mustbe continually applied on operating arm 46 until the center line oflever arm 61, pin 63 and pin 54 are again. aligned. At this instant, theforce of spring 62 reacting on crank actuator 53 is directly against itspoint of rotative connection, pin 54. And up until this point said forceof spring 62 has been in a direction under said point of rotation 54 andmaintaining ear 56 of crank actuator 53 against stop 59 in the positionshown.

Any further rotative movement of operating arm 46 causes the force ofspring 62 to be applied to the other side of pin 54 and to ensure thedesired positive snap action, pin 63 moves to the other end of slot 58thereby causing the force of spring 62 to react strongly against crankactuator 53 forcing it to rotate about pin 54 until car 55 engages stop59 as shown in FIGURE 5.

The rotation of crank actuator 53 from the position shown in FIGURE 6 tothat shown in FIGURE 5 causes slot 60 therein to be moved upward. End 67being positioned in said slot 60 is likewise moved, rotating crank 66about pin causing fork end 69 to move away from base 10 in an outwarddirection. Fork end 69 moves pin 70 wit-h it forcing contact arm 71 tobe moved outward. This disengages said movable contacts from theirrespective associated stationary contacts with a snap action, therebyopening the circuit. It is to be noted that the force created by springs78 assist in the snap movement of the mechanism and the opening of saidcontacts.

In the rotation from the on position to the off position, that is fromFIGURE 6 to FIGURE 5, the traversing of pin 47 through slot 48 servestwo important safety features.

First, should spring 62 break while the switch is in its on conditionthe movement of operating arm 46 from its on position to the otfposition causes pin 47 to engage crank actuator 53 and force it torotate to a certain degree about pin 54. This degree of rotation issuflicient to cause said movable contacts to disengage from saidassociated stationary contacts. Thus, the switch is forced by directmechanical connection to be moved to its off position.

Should the movable contacts become welded through arcing to theirassociated stationary contacts, it is undesirable and extremelydangerous to allow operating arm 46 to be moved to its oif' position.This is prevented because of the aforedescribed mechanical contact ofpin 47 with crank actuator 53. This physical contact of pin 47 preventsoperating arm 46 and toggle lever arm 43 from being rotated far enoughto allow the center line of lever arm 61 to go beyond the aforedescribedaligned center lined position. Therefore, since toggle lever arm 43cannot move lever arm 61 beyond its over center position, the force ofspring 62 will cause the mechanism to snap immediately back to the OEposition as soon as the rotative force is removed from operating arm 46.

With reference to FIGURE 7, there is shown additional mechanism shouldit be desired to operate the switch mechanism from the side. Thismechanism consists of a stationary link 80 having an S-shape and whichhas one end secured to the underside of base 10 by means of screws 81and the other end extends over the other mechanism. Rotatively attachedto stationary link 80 by means of pin 82 is a lever arm actuator 83.Stationary link 80 is positioned to place pin 82 in the same axis as pin44. A side operating arm 84 is rotatably secured to lever arm actuator83 by means of a pin 85. Pin 85 is spaced away from pin 82 by the samedistance that operating arm 46 is spaced away from pin 44.

The free end of lever arm actuator 83 is secured by a pin 86 in hole 52in end 49 of toggle lever arm 43.

To operate the mechanism from the off position to the on position, it isonly necessary to supply a force on operating arm 84 in the directiontowards the switch. This force causes lever arm actuator 83 to rotateabout pin 82, and moves end 49 of toggle lever arm 43 with it. Theswitch mechanism then operates in the same manner as described when anoperating arm is used in front of the switch.

To move the switch from its on position to its off position, the forceon operating arm 84 should be reversed. That is, the force should bepulling operating arm 84 away from the switch. This force draws leverarm actuator 83 with it and moves end 49 of toggle lever arm 43 througharcuate slot 50.

With this mechanism it is possible to transmit a straight line motionfrom the side or any angle to the switch to the rotative movementnecessary to operate the switch.

If an arcuate motion or direction of force is available, it can beconnected directly to end 49 of toggle lever arm 43. In the foregoing, Ihave described my invention only in connection with preferredembodiments thereof. Many variations and modifications of the principlesof my invention within the scope of the description herein are obvious.Accordingly, I prefer to be bound not by the specific disclosure herein,but only by the appending claims.

I claim:

1. An electric switch comprising a base plate, an insulated housingmounted on the one side of said plate and having a plurality of arcchambers formed therein, a pair of stationary contacts supported inspaced apart relationship in each of said are chambers, a movablecontact associated with each pair of said stationary contacts andvisibly supported in said are chambers for reciprocal movement between acontact engaging and a contact disengaging position by a contact arm,said contact arm disposed in the recess in said housing perpendicular tosaid plate, a crank pivotally mounted on said base plate and located insaid recess and having one end thereof connected to said contact arm.and a second end thereof extending through a slot in said plate, acrank actuating member rotatively secured to the opposite side of saidplate and positioned to engage the second end of said crank, a snapacting lever arm located at the opposite side of said plate, a pinpivoting the inner end of the lever arm to said crank actuating member,a toggle arm connected to the other end of said lever arm at theopposite side of said plate and rotatably secured thereto at the oneside thereof, a spring circumscribing said lever arm and reactingbetween it and said toggle arm to provide a force for rotating saidcrank actuating member about said pin with a snap action, an operatingarm secured to said toggle arm for imparting rotative movement theretoto actuate the snap acting lever arm and thereby effect engagement anddisengagement of the contacts as the contact arm is actuated by thecrank and crank actuating member.

2. An electric switch comprising a base plate, an insulated housingmounted on the one side of said plate and having a plurality of arcchambers formed therein, a pair of stationary contacts supported inspaced apart relationship in each of said arc chambers, a movablecontact associated with each pair of said stationary contacts andvisibly supported in said are chambers for reciprocal movement between acontact engaging and a contact disengaging position by a contact arm,said contact arm disposed in a recess in said housing perpendicular tosaid plate, a crank pivotally mounted on said base plate and disposedwithin said recess and having one end thereof connected to said contactarm and a second end thereof extending through a slot in said plate, acrank actuating member rotatively secured to the opposite side of saidplate and positioned to engage said second end of said crank, a snapacting lever arm located at the opposite side of said plate, a pinpivoting the inner end of the lever arm to said crank actuating member,a lever actuator connected to said lever arm, a stationary link securedto the opposite side of said plate and rotatably supporting the leveractuator, a spring circumscribing said lever arm and reacting between itand said lever actuator to provide a force for rotating said crankactuating member with a snap action, and an operating arm rotatablyconnected to said lever actuator in spaced relation to the connection tothe link and projecting from the base plate in a plane parallel to thebase plate, said operating arm being generally rectilinearly movable forimparting the required operating movement to the lever actuator andthereby effect opening and closing of the contacts as the contact armactuator is actuated by the crank and crank actuating member.

3. An electric switch comprising a base plate, stationary and movablecontact means associated with each other and mounted on one side of thebase plate, a snap actuating mechanism mounted on the opposite side ofthe base plate and including a crank actuator with an arcuate slottherein rotatively pivoted to the base plate and snap acting meanspivoted at its inner end'to the actuator within said arcuate slot andadapted to rotate the actuator with a snap action, 'a toggle arm pivotedat the inner end ,to the base and secured at the outer end to the outerend .by the operating member.

4. An electric switch as set forth in claim 3 wherein the base plate hasan arcuate slot therein at the location of the operating member, and anextension on the operating member projecting through the arcuate slotand disposed to engage the crank actuator when the operating member isrotated from an on to an off position and rotate the crank actuator witha sufiicient degree of rotation to disengage the contacts in the eventthat the snap actuating mechanism fails to operate.

5. An electrical switch comprising a mounting platelike base having afirst side and a second side, an insulated housing mounted on the firstside of the base, stationary contacts supported by said housing, atoggle arm located on the first side of the base and pivoted at itsinner end to said base, and the base having an arcuate slot adjacent theouter end of the toggle arm, a projection on the outer end of the togglearm extending through the arcuate slot towards a second side of thebase, a crank actuator, pivot means pivoting the crank actuator to thebase on the second side of the base, and said actuator having anoutwardly turned car at the inner end with an arcuate slot therein andspaced ears at the outer end, a stop member secured to the base betweenthe spaced ears of the actuator to regulate the rotational movement ofthe crank actuator, a lever arm secured at the outer end thereof to theprojection of the toggle arm, a pin extending through the slot in thecrank actuator and securing the inner end of the lever arm to the crankactuator, a spring assembled around the lever arm and adapted to apply arotative force on the crank actuator, a crank supported at the firstside of the base and having a projection extending through the base andinto operative engagement with the crank actuator, a contact carrier armreciprocally disposed at the first side of the base and coupled with thecrank for reciprocation by the crank, movable contacts secured to thecontact carrier and disposed to engage and disengage the stationarycontacts upon reciprocation of the contact carrier, and an operatingmember secured to the toggle arm and extending outwardly from said baseto actuate said arm and crank actuator, and movement of the operatingmember effecting snap action separation and engagement of the movablecontacts and fixed contacts upon movement of the lever arm beyond acenter line axis extending through the lever arm, and through the pinsecuring the lever arm and crank actuator together and the pivot meansof the crank actuator.

6. The electric switch of claim 1 wherein each of said movable contactsis resiliently mounted on the contact arm with resilient means biasingthe contacts to contact closed position.

References Cited by the Examiner UNITED STATES PATENTS 2,479,266 8/ 49Rowe 200-67 2,800,547 7/57 Johnson 200 77 2,995,043 8/61 Lusk et a1.200-67 BERNARD A. GlLHEANYpPl'imary Examiner.

ROBERT K. SCHAEFER, Examiner.

3. AN ELECTRIC SWITCH COMPRISING A BASE PLATE, STATIONARY AND MOVABLECONTACT MEANS ASSOCIATED WITH EACH OTHER AND MOUNTED ON ONE SIDE OF THEBASEPLATE, A SNAP ACTUATING MECHANISM MOUNTED ON THE OPPOSITE SIDE OFTHE BASE PLATE AND INCLUDING A CRANK ACTUATOR WITH AN ARCUATE SLOTTHEREIN ROTATIVELY PIVOTED TO THE BASE PLATE AND SNAP ACTING MEANSPIVOTED AT ITS INNER END TO THE ACTUATOR WITHIN SAID ARCUATE SLOT ANDADAPTED TO ROTATE THE ACTUATOR WITH A SNAP ACTION, A TOGGLE ARM PIVOTEDAT THE INNER END TO THE BASE AND SECURED AT THE OUTER END TO THE OUTEREND OF THE SNAP ACTING MEANS, AN OPERATING MEMBER SECURED TO THE TOIGGLEARM TO ROTATE THE SAME AND EFFECT ACTUATION OF THE SNAP ACTING MEANSWHEN A CENTER AXIS LINE EXTENDS THROUGH THE PIVOTS OF THE CRANK ACTUATORAND THE SNAP ACTING MEANS, AND A CRANK SECURED TO THE BASE PLATE ANDEXTENDING THERETHROUGH IN ENGAGEMENT AT ONE END WITH THE CRANK ACTUATOROF THE SNAP ACTUATING MECHANISM AND AT THE OTHER END WITH THE MOVABLECONTACT MEANS TO OPEN AND CLOSE THE CONTACT MEANS BY A SNAP ACTION WHENTHE TOGGLE ARM AND SNAP ACTUATING MECHANISM ARE ACTUATED BY THEOPERATING MEMBER.